/*
 * Copyright (c) Microsoft Corporation
 *
 * All rights reserved.
 *
 * MIT License
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
 * documentation files (the "Software"), to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and
 * to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of
 * the Software.
 *
 * THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
 * THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package com.microsoft.azure.oidc.future.impl;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.microsoft.azure.oidc.exception.PreconditionException;
import com.microsoft.azure.oidc.future.FutureHelper;

public class SimpleFutureHelper implements FutureHelper {
    private static final FutureHelper INSTANCE = new SimpleFutureHelper();
    private static final Logger LOGGER = LoggerFactory.getLogger(SimpleFutureHelper.class);

    @Override
    public <T> T getResult(Future<T> future) {
        if (future == null) {
            throw new PreconditionException("Required parameter is null");
        }
        try {
            while (!future.isDone() && !future.isCancelled()) {
                Thread.sleep(10);
            }
            if (!future.isCancelled()) {
                return future.get();
            }
        } catch (InterruptedException | ExecutionException e) {
            LOGGER.error(e.getMessage(), e);
        }
        return null;
    }

    public static FutureHelper getInstance() {
        return INSTANCE;
    }
}
